Field of the Invention
The present disclosure relates to a post-processing apparatus, more particularly, a post-processing apparatus having a punching function.
Description of the Related Art
Conventionally, post-processing apparatuses for punching a hole for binding or the like in a sheet have been known. Among these post-processing apparatuses, some post-processing apparatuses have a function of correcting a position of punching a sheet.
Regarding the art of correcting a position of punching a sheet, Japanese Laid-Open Patent Publication No. 2009-190837 discloses a sheet transporting apparatus including a transporting roller for transporting a sheet, wherein a CIS is provided to measure a position of a side end portion of the sheet transported by the transporting roller.
Moreover, Japanese Laid-Open Patent Publication No. 2013-053006 discloses a configuration including: first detecting means and second detecting means for detecting respective end portions of the sheet in the width direction, the sheet being arranged and transported along the sheet width direction; and correction means for correcting deviation of the sheet in the width direction by moving the sheet in the width direction based on a detected position of a first end portion in the width direction by the first detecting means, a detected position of a second end portion in the width direction by the second detecting means, and an amount of transportation of the sheet from the detected position in the transportation direction by the first detecting means to the detected position in the transportation direction by the second detecting means.
Moreover, in order to improve workability for an initial setting on a punching process, Japanese Laid-Open Patent Publication No. 2006-35557 discloses an image processing system configured to include: an image processing apparatus; and a post-processing apparatus configured to adjust a stop position of a sheet supplied (discharged) from the image processing apparatus by controlling transporting means (transporting roller or the like) for transporting the sheet and to punch the sheet having stopped being transported. More specifically, the post-processing apparatus detects a position of a punch hole based on an image of the punch hole on the sheet scanned by the image processing apparatus.
Regarding an art of avoiding punching at a portion at which an image is to be formed, Japanese Laid-Open Patent Publication No. H05-104880 discloses an image forming apparatus including: a hole providing unit for providing a hole in the sheet for the purpose of binding; and a transporting unit for transporting the sheet to/from the hole providing unit, wherein detecting means is provided to detect, in advance, presence/absence of an image at a hole provision position of the sheet and output it when the hole providing unit provides a hole in the sheet, and in response to the output of the detecting means, when there is the image at the hole provision position in the sheet, the hole providing unit and the transporting unit are controlled to provide a hole after moving the sheet to a position at which the image is not detected by the detecting means.
Regarding an art of indicating a pattern of punch hole positions or the like, Japanese Laid-Open Patent Publication No. H08-331361 discloses a copying/printing machine provided with: sheet information detecting means for detecting a size of a sheet of a print document or copy document and detecting an arrangement thereof on a transportation path in order to indicate a punch hole position indication or ruled line frame at a predetermined position of the sheet; and pattern signal generating means for generating a pattern electric signal for indicating a predetermined pattern on a predetermined portion of the sheet at its peripheral portion on the transportation path based on the output signal of the sheet information detecting means, wherein a composite signal of the indication electric signal and the pattern electric signal is supplied to indicating means.